Selector mechanism for zigzag sewing machines



Dec. 12, 1961 w. STERNBERG 3,012,527

SELECTOR MECHANISM FOR ZIGZAG SEWING MACHINES Filed Aug. '7, 1958 2Sheets-Sheet 1 Dec. 12, 1961 W. STERNBERG SELECTOR MECHANISM FOR ZIGZAGSEWING MACHINES Filed Aug. 7, 1958 2 Sheets-Sheet 2 3,012,527 PatentedDec. 12, 1961 ice 3,012,527 SELECTUR MECHANISM FOR ZIGZAG G MACHHNESWilli Sternberg, Karlsruhe-Durlach, Germany, assignor to Gritzner-KayserAlrtiengesellschaft, Karlsmhe-Durlach,

Germany Filed Aug. 7, 1958, Ser. No. 753,680 Claims priority,application Germany Aug. 10, 1957 11 Claims. (Cl. 112-458) v Thisinvention relates to sewing machines constructed to turn out decorativedesigns and fancy stitch patterns besides straight seams.

More particularly this invention relates to improvements in the selectormechanism which is operable for working a change-over from one patternto another.

In such a selector mechanism a plurality of cam members or contour discseach representing the control'element for a respective stitching patternare mounted coaxially upon a drive shaft cooperative with oscillatablemeans having driving connection with the needle bar guide in such amanner that the oscillatable means are oscillated selectively by aselected cam member incident to rotation of the drive shaft. Theoscillatable means comprise cam follower means or feelers which can bemade to cooperate with any one of the cam members, said means beingconstructed for imparting the oscillatory motion to be transmitted tothe needle bar guide, selectively via the cam follower means.

It is one of the objects of the invention to provide means affordingcompletely automatic stitch variations or change-over from one stitchpattern to another even during the operation of the sewing machine, andsimultaneously facilitating in a positive manual control a visiblechange-over from one stitch pattern to another selected at will by anoperator.

A more specific and important object of the invention is to provideselector means so constructed as to facilitate the arrangement andassembly of a predetermined number of different cam discs coaxially in aset or pack in a preferred sequence, yet so that even with the more frequently employed cam discs spaced a substantial distance from eachother, the followe or feeler means may be adjusted and positionedrapidly and effortless to the respective selected disc by the operator.

Accordingly, a relatively long axial distance between often employed camdiscs can be significantly reduced to a very slight movement to beperformed via one of the feelers by the operator.

Another object of the invention is to provide a selector mechanismresulting in a very compact sewing machine structure with a relativelyreduced number of parts, of simplified construction, requiring only aunique and convenient manipulation by the operator for selecting adesired stitch pattern, and which presents a highly attractive andbalanced appearance inasmuch as numerous control knobs, levers andcontrol elements are eliminated, which have heretofore complicated theoperation of known sewing machines.

Still another object of the invention is to provide a simple andeffective selector mechanism whereby the selection of a certain stitchpattern among a large number of stitch designs can be carried out withgreat ease and accuracy in a minimum of time, due to the manipulation ofa single control knob or element by the operator.

According to the invention, these objects are attained by providing aselector arrangement in which a feeler or follower unit comprising aplurality of feeler members is shiftable or slidable along a pathparallel to the axis of the pack of cam discs, each of the feelermembers or fingers being individually swingable on a carrier into andout of operative position relative to the respective disc, with theaxial spacing of the feeler members on the carrier so arranged that eachfeeler when the unit is shifted axially, will cover its proportionateshare of the total length or extent of the pack of discs. This shiftablefeeler unit cooperates with an oscillator frame extending along the pathof axial movement of the feeler unit and thus at least along theeffective length of the pack, arranged to be rockable, preferably aboutthe axis of feeler fingers for actuating the needle guide throughsuitable transmission means.

In order to control the operating relationship between the feelerfingers and the discs, special automatic blocking means are provided andso arranged that when the feeler unit is shifted axially to apredetermined or selected position identifying a desired stitchingpattern, only one of the feeler fingers will have operative contact withthe effective cam face or contour of the selected disc to rock theoscillator frame in accordance with the rotation of the pack, said framethus actuating or oscillating the needle bar to produce the selectedstitching pattern.

If preferably only two such feeler fingers are carried by the unit, theyare axially spaced a distance substantially half of the effective lengthor extent of the pack, so that whenever one of these fingers is broughtto a position relative to a selected disc, the other fingerautomatically becomes inoperative, and vice versa. In this way, thefeeler unit need only be shifted a very short distance along the packfor effecting a change-over between cam discs or respective stitchingpatterns, which may be spaced at considerable axial distance from eachother in the pack. Thus even in a very long pack containing a largenumber of discs, each disc may be reached swiftly and easily in aminimum of time by way of only a very short movement of the feeler unitby a slight turn of control knob or other manipulating element.

Features lie further in the provision of blocking means preferably inthe form of a backing bar carried by the oscillator frame and presentingto the feeler fingers, opposite to the pack, a series of projections orabutments alternating with recesses both cooperating with the feelerfingers in a special manner to render them operative or inoperative asneeded.

Other features reside in the provision of compact and convenientactuating means whereby the shifting of the feeler unit betweenstitching patterns can be readily and rapidly effected.

Still other features reside in the provision of simple and effectiveautomatic deactivating means for rendering all feeler fingerssimultaneously inoperative or neutral and clear of both the cam pack andthe backing means preparatory to performing the axial shifting of thefeeler unit for a change-over between stitching patterns.

These and other objects of the invention will become further apparentfrom the following detailed description, reference being made to theaccompanying drawings showing a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a fragmentary side elevational view of the selector mechanismembodying the invention and shown partly in section; and

FIG. 2 is a top plan view, partly in section, of the mechanism of FIG. 1showing particularly the control element and actuating means for thefeeler unit.

According to a preferred embodiment and by way of example, the inventionis herein illustrated in a mechanism organized for operation with onlyone pair of alternatingly engageable feeler fingers mounted on theslidable unit, although this arrangement does not exclude other possiblearrangements providing more than two such companion feeler fingers. Forexample, if three were chosen the maximum shifting movement required forpositioning would at no time exceed one-third of the total effectiveextent or length of the cam disc pack, whereas with the twin-follower orfinger arrangement herein shown, the maximum shifting movement isone-half of the aforesaid total length of the pack.

Referring now particularly to the drawings, a needle bar 1 islongitudinally slidable in a known manner in a needle guide 2 having atits upper end a pivotal connection 3 with the frame of the machine, soas to be capable of swinging movements imparted thereto by areciprocatory actuator rod 4. This actuator rod 4 is reciprocated by aguide lever 5 which has an upwardly extending arm 6 pivotally connectedto one end of a link member 7 the other end of which has a pivotalconnection with an oscillating frame 8.

This oscillating frame 8 is rockable upon a shaft 9 upon which isslidable or axially shiftable sleeve or carrier 10 upon which aremounted a pair of feeler fingers 11 and 12 which together with thecarrier 10 constitute a feeler unit U that is shiftable axially upon theshaft 9 parallel to a drive shaft 16 carrying a pack of coaxiallyaligned cam members or contour discs 17 the function of which will bedescribed below. It will be understood, however, that the feeler unit Uis shiftable along the effective length of the pack of discs by suitableactuating means in the operation of the selector mechanism as will befurther described.

The actuating and positioning means for shifting the feeler unit U uponshaft 9 comprises a nut 13 operating on a threaded spindle 14, andoperatively so connected with the sleeve 10 of the feeler unit thatrotation imparted to the spindle by the operator may move the nut 13 andsleeve 10 together parallel to the shaft 16 carrying the pack of contouror cam discs rotated by the drive of the machine.

The feeler fingers 11 and 12 are mounted turnable upon the sleeve 10,each being under the influence of spring means 18 tending to urge thefingers to a position out of contact with the discs 17 and into contactwith a backing bar 19 which in this embodiment constitutes the top endmember of the horizontally elongated oscillating frame 8.

The backing bar 19 is preferably in the form resembling that of atoothed rack providing along the length thereof and opposite the pack aseries of projections or teeth 20 alternating with recesses 20 thespacing being such that two sequential teeth together with their twoassociated recesses will correspond to the spacing of the contour discs17 carried by the shaft 16, with the teeth 20 representing abutments orprojections with faces for engagement by the feeler fingers in themanner presently to be described.

The two feeler fingers 11 and 12 are formed opposite the cam disc packwith abutment edge portions 21 and 22, respectively, so arranged andshaped as to cooperate with the toothed backing bar 19 in the operationof the selector mechanism. For instance, when the feeler unit U is sopositioned that the edge portion 21 of the one feeler finger registersin abutting relationship with a tooth 20 and thus in operatingrelationship with the selected cam disc, spring means 18 will urge theedge portion 22 of the other feeler finger 12 into a recess or gap 20between two teeth and thus clear of the reach of the remaining cam discsand out of operative relationship therewith.

At the same time, a spring S attached to a downward arm A of heoscillating frame will tend to permanently urge the frame together withthe feeler fingers towards the pack of discs.

In a practical instance this is accomplished by having the width of theabutment edges 21 and 22 correspond to one-half of the width of thediscs 17, with the two feeler fingers spaced from each other half thedistance of the sum total of the widths of all the discs.

In the example herein illustrating the invention there are twenty-onesuch discs 17 assembled in the pack or set of cams. Hence, the spacingbetween the feeler fingers is such that when the feeler unit is axiallypositioned with the feeler finger 11 registering with the first one ofthe discs 17, the abutment edge 21 thereof will engage the abutment faceof a tooth 20 of the backing rod 19, with the second feeler finger 12then registering with the space between the eleventh and the twelfthdisc 17, and the abutment edge 22 of the finger registering with thespace or recess 20*- between two teeth.

Thereupon, when the feeler finger unit U is shifted to the extent ofhalf the width of a disc 17, such shifting will bring the feeler finger12 into registry with the cam disc 17, whereby nose or abutment edge 22thereof engages a tooth or projection 26, while the first feeler finger11 will now register with a gap or recess 20 between a pair of teeth andurged by spring means 18.

Thus it will be understood that whichever feeler finger is backed by theabutment face of a tooth is thereby placed into operative positionrelative to the respective selected disc, whereas the companion feelerfinger is angularly displaced and with its abutment edge portion lodgingin a gap is thereby placed into an inoperative position relative to itsopposing disc. Thus, in the sewing operation itself, a selected cam disc17 engaged by a respective feeler finger and rotated by the drive of themachine will impart rocking movements to the oscillating frame inaccordance with the contour or configuration of the disc, and suchrocking movements will be transmitted through parts 7, 6, 5, 4 to theneedle guide and needle bar, whereby a desired selected stitch patternis effec tuated.

There will now be described the actuating mechanism whereby the threadedspindle 14 may be rotated for the purpose of positioning the selectormeans to effect a changeover from one stitch pattern to another, evenwithout necessitating the interruption of the sewing operation.

This actuating mechanism comprises a spur gear 23 fixed on one end ofthe spindle, and a meshing spur gear 24 formed with a hub portion 26carried in a journal 27 on the frame of the machine and secured againstaxial displacement. The gear 24 fits over a sleeve 23 rotatable about arod 29 and carrying rotatably therewith a control knob 25 held in placeby capstan 30, the sleeve with the control knob being axiallydisplaceable in gear 24 and its hub 26.

The control knob 25 has coupling means or portions 31 adapted tointerengage with complementary coupling means or portions 32 formed onthe hub portion 26 of spur gear 24. It will thus be seen from FIG. 2that depressing the control knob 25 will couple the same with gear 24,while accordingly shifting the sleeve 28 inwardly. Thereupon, thecontrol knob 25 may be rotated so that through gears 24 and 23 thethreaded spindle 14 may be turned to move the nut 13 and throughcoupling arm 15 to move the feeler finger unit U axially parallel to thepack of discs to a position identical to a selected stitching patternrepresented by the respective disc.

However, while executing this axial shifting movement of the feelerunit, it is necessary that both feeler fingers 11 and 12 thereof be sopositioned as to be clear of the discs of the pack. Mechanism to thisend comprises a cam sleeve 33 constituting in effect a continuation ofsleeve 28 and connected thereto as indicated by a set screw 28 or thelike, and having a conically shaped terminal cam face 34 engaged by thefirst arm 35 of a lever element 37 formed with a second arm 38 which inturn is adapted to engage a projection or lug 39 provided upon adownward arm B of the oscillating frame 8.

Thus, when the control knob 25 is depressed, this will cause the arm 35to ascend upon the conical cam face 34 to rest upon the adjoiningcylindrical portion of sleeve extension 33, imparting to the leverelement 37 a slight angular movement counter clockwise, this in turnworking the oscillating frame 8 clockwise through a corresponding angle.

With the spring means 18 permanently urging both feeler fingers 11 and12 against the backing bar 19 of the Oscillating frame, it is now clearthat this angular movement imparted to the oscillating frame by themanual depression of control knob 25 will swing the feeler fingers awayfrom the pack of discs to a position out of reach and inoperative withrespect to the discs.

Yet, in order to clear the feeler fingers for axial shifting of thefeeler unit, it is also necessary that the abutment edge portions 21 and22 thereof be clear of the recesses in the backing bar 19. To this end,an abutment bar 40 is mounted on the frame of the machine extendingparallel to the axis of the oscillating frame and adjacent to thebacking bar 19. This abutment bar 40 is so arranged as to arrest theangular movement of the feeler fingers relative to the oscillating frameby engaging the abutment edge portions 21 and 22 thereof preferably justabove the backing bar 19 while allowing the oscillating frame tocontinue swinging away slightly from the arrested feeler fingers asufficient distance to ensure that they are clear of the backing bar 19as long as the control knob 25 is depressed and coupled to the actuatingmechanism.

Advantageously, the improved selector mechanism of this invention withactuating means therefor may be cooperatively associated or coupled withan indicator mechanism as disclosed in copending application Serial No.744,555, in which a pointer moves along a scale presenting the variousstitching patterns, in accordance with the positioning of the selectormechanism.

Various changes and modifications may be made without departing from thespirit and scope of the present invention and it is intended that suchobvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

l. A selector mechanism for a sewing machine comprising operable knobmeans, an oscillatory frame, a rotatably driven shaft, a set of camdiscs mounted on said shaft for rotation therewith, swingably supportedfeeler means interconnecting said oscillatory frame with one of said camdiscs for achieving a stitch pattern corresponding to said one cam disc,said feeler means being arranged for displacement in unison lengthwiseof and parallel to said shaft and including two feeler fingers arrangedin spaced apart relation to each other so that when one of said feelerfingers is located in contact and in registry with one of said cam discsthe other feeler finger is disposed adjacent and out of registry withanother cam disc positioned at half the extent of said set of cam discs,spring means normally urging said feeler fingers out of contact withsaid cam discs, said oscillatory frame including a rack provided withteeth alternating with recesses, said one feeler finger engaging arespective tooth of said rack in operative position with said otherfeeler finger being urged by said spring means into a correspondingrecess between two teeth into inoperative position so that upon rotationof said shaft on which said cam discs are mounted, said one feelerfinger is agitated by the respective cam disc for translating movementof the latter via said one feeler finger and said respective tooth ontosaid oscillatory frame, and means operatively connected with said knobmeans for displacing said feeler means lengthwise of said set of camdiscs for alternatingly bringing into engagement said other feelerfinger with another tooth of said rack and said one feeler finger with arespective recess thereby to deactivate said one feeler finger.

2. A selector mechanism according to claim 1, including a sleeve member,elongated means mounting said sleeve member for parallel displacement tosaid shaft, said feeler fingers being supported by said sleeve member insaid spaced apart relation, said feeler fingers being provided withrespective nose-shaped ends forced under the action of said spring meanstoward said rack, said rack having a pitch, said pitch beingpredetermined so that upon displacement of said sleeve member lengthwiseof said mounting means one of said feeler fingers alternates with theother feeler finger in first registering with and engaging a tooth ofsaid rack thereby overcoming the action of said swing means for contactwith a selected cam disc and then during further displacement becomesspaced from said selected cam disc for subsequent registry with a recessbetween two adjacent teeth thereby to deactivate said one feeler fingerand engaging said other feeler finger with a respective tooth of saidrack to effectuate contact of said other feeler finger with anotherselected disc of said set of cam discs.

3. A selector mechanism according to claim 1, wherein the distancebetween said two feeler fingers corresponds to about one-half of theextent of all the cam discs in pack assembled condition plus one-half ofthe width of a respective cam disc, the pitch of said toothed rackcorresponding to said one-half of the width of said respective disc ofsaid pack of cam discs, each feeler finger being provided with anose-shaped end dimensioned to engage a respective recess formed betweentwo adjacent teeth of said rack and corresponding to said pitch.

4. A selector mechanism for a sewing machine comprising, in combination,a driven shaft, a pack of rotatable cam discs carried by said shaft,each disc representing a respective stitch pattern, an oscillating framerockable about an axis parallel to said shaft and extending at least theeffective length of said pack, said frame having a plurality of teeth,at least a pair of feeler fingers having a common turning axis, at leastone finger engaging one of said discs and engaging the teeth of saidoscillating frame for rocking said frame upon rotation of said one disc,spring means for urging said fingers against said frame, said fingersbeing spaced a predetermined axial distance from each other and movabletogether axially as a unit parallel to said shaft as well as along saidosciliating frame for positioning one of said feeler fingers foroperative engagement with said selected disc, said oscillating frame andsaid feeler fingers being so constructed and arranged that upon rotationof said pack said one disc will through said one feeler finger rock theframe, the other of said feeler fingers being angularly displacedrelative to said first mentioned finger and thereby rendered inoperativerelative to said discs by passing between said teeth, and means causingsaid feeler fingers to be alternately and mutually exclusivelyengageable with a respective selected disc each within a predeterminedrange of the extent of the disc pack.

5. A selector mechanism for a sewing machine operable to select a stitchpattern; comprising a drive shaft, a pack of cam discs carried by saidshaft and rotatable therewith, each disc representing a respectivestitch pattern, an oscillating frame rockable about an axis parallel tosaid shaft, said frame having a plurality of teeth substantiallycorresponding in number to the number of said discs, a pair of feelerfingers having a common turning axis, each finger engaging selecteddiscs of said pack, at least one finger engaging said frame, said feelerfingers being spaced a predetermined axial distance from each other andmovable axially as a unit parallel to said shaft as well as along saidoscillating frame for positioning one of said feeler fingers forcooperative engagement with a selected disc, spring means forpermanently urging each feeler finger toward said frame and in adirection away from said disc pack, said frame teeth and said feelerfingers being so constructed and arranged that upon rotation of saiddisc pack the selected disc will rock the frame via said one feelerfinger engaging one of said teeth, the other finger being held withdrawnby said spring means between said teeth and thereby rendered inoperativerelative to said discs, whereby said feeler fingers are alternately andmutually exclusively engageable with a respective selected disc.

6. A selector mechanism for a sewing machine comprising a drive shaft, apack of cam discs carried by said shaft and rotatable therewith, eachdisc representing a respective stitch pattern, an oscillating framerockable about an axis parallel to said shaft 'and extending at least.the effective length of said pack, a pair of feeler fingers having acommon rotatable axis, at least one finger engaging a selected disc aswell as engaging said oscillating: frame, said fingers being spaced apredetermined axial distance from each other and movable axially as aunit parallel to said shaft as well as along said oscillating frame forpositioning one of said feeler fingers at a time for cooperativeengagement with a selected disc thereby to rock the frame by therotation of the selected disc, first spring means for permanently urgingeach feeler finger against said frame in a direction away from saidpack, second spring means for urging said frame together with saidfeeler fingers towards said pack of discs, and means for mutuallyexcluding said feeler fingers from engagement by said discs andcomprising a series of projections alternating with recesses provided onsaid frame along a length corresponding at least to the effective lengthof said pack and so arranged that each finger when positioned forcooperative engagement with a selected disc is backed by a projection ofsaid series while urged by said second spring means towards said pack,while said other of said feeler fingers is angularly displaced relativeto the first-mentioned finger into a respective recess of the series bythe action of said first spring means.

7. A selector mechanism for a sewing machine comprising a plurality ofcams rotatable on a common axis having effective side faces, anoscillatable member adjacent said cams for transmitting motion inaccordance with the outline of a selected one of said cams, and followermeans including at least two separate follower members selectivelyengageable with said cams, means supporting said follower membersadjacent said cams, said follower members being shiftable along saidsupporting means in a direction traversing the effective side faces ofsaid cams to align at least one of the follower members with a selectedcam, and means defined on said oscillatable member located tooperatively connect one of said follower members and said oscillatablemember to the selected one of said cams whereby to move saidoscillatable member in accordance with the outline of the selected oneof said cams. said means including means located to simultaneouslyoperatively disconnect the other of said follower members from saidoscillatable member from said cams.

8. A selector mechanism according to claim 7, wherein said supportingmeans for said follower members includes a spindle member, said followermembers being displaceable together along said spindle member.

9. A selector mechanism according to claim 7, wherein said means forselectively connecting one of said follower members includes a rackmember having spaced teeth, said follower members being laterally spacedso that one of said follower members aligns with a tooth portion whenthe other aligns with a recess between the teeth and vice versa.

10. A selector mechanism for a sewing machine comprising a plurality ofcams rotatable on a common axis, a follower shaft disposed adjacent saidplurality of cams, an oscillatable member on said follower shaft fortransmitting motion in accordance with the outline of a selected cam,first and second follower members slidable on said shaft and each beingmovable into alignment with and operative engagement with one of saidcams, and means defined on said oscillatable member and located tooccupy the space between one of said follower members and saidoscillatable member connecting one of said members to said oscillatablemember and the selected one of said cams for transmission of the motionof the cam outline of which the follower is in contact and located toclear the space between the other of said follower members and saidoscillatable member.

11. A selector mechanism according to claim 10, wherein said meansdefined on said oscillatable member includes a rack having spaced teeththereon, the spacing being such that the teeth contact one of saidfollower members when the other of said follower members lies in a spacebetween the teeth.

References Cited in the file of this patent UNITED STATES PATENTS2,675,451 Tinus Apr. 13, 1954 2,747,417 Brown May 29, 1956 2,764,895Bono Oct. 2, 1956 2,832,302 Gegauf Apr. 29, 1958 2,862,468 Johnson 2.Dec. 2, 1958 FOREIGN PATEITS 19,184 Great Britain Sept. 12, 19081,095,914 Great Britain Dec. 29, 1954 548,344 Italy Sept. 24, 19561,004,465 Germany Mar. 14, 1957

